ADM

ADM BWF

(Audio Definition Model Broadcast Wave Format) is a file format used for mastering Dolby Atmos mixes. It’s essentially a WAV file containing both the audio and metadata necessary for a Dolby Atmos renderer to recreate the mix, including bed tracks, object tracks, and panning information.

About Dolby Atmos ADM files

by Jan Printz August 2025

The spatial format is from 2012. It contains a lot of channels placed in the socalled bed and/or objects. The ‘bed’ channels (0 – 10) and/or objects channels (0 – 118, but maybe a home Atmos Receiver only can decode up to 16 objects and a lot of cinemas 32… but that is to be determinated) So ADM can also contain only bed or only objects channels.

The bed is normally used for tracks that are more stationary and goes only up to 7.1.2 (the 10 channels where .2 stands for a left and right side ceiling channel). But nowadays most Spatial mixers use a 7.1.4 setup and if they place a track in the front OR back ceiling channel it will go to both front and back due to the .2 side ceiling format. So objects are needed here instead and some use only those.

Therefore my approach with Atmos mixes from 50 to 150 original tracks is using a 7.1 bed for the audio at ground level and all the tracks going up over the ground level to a single 7.1.4 group that will be used as 11 objects (from 7.0.4 because no LFE are needed for objects).

As I see it it will work the best way for all systems up to 7.1.4 and the best compromise for the old format. Especially when the spatial mix comes from 40 to 150 tracks and each stereo instrument/vocal track will take up 2 objects.

So a ADM file a number of bed/objects channels and some metadata telling where the objects are placed or move to. Because of that the ADM wav files are not correctly played on normal media players on a computer, where the metadata of the object positions is ignored.

ADM can be downgraded into E-AC3 (Dolby Digital Plus up to 1024 kbps) as a part of mp4 with video. It is downgraded to compressed 5.1 bit with some of the objects added. Here for an example AWS Media Convert can be used.

I can only find one ADM player for computers, but it’s free:

Dolby Atmos Composer Essential from fiedler-audio.
It is a plugin for a DAW like Cubase, Pro-Tool, Logic and the (almost?) free Reaper.

It can play one ADM file at the time by loading the file down in the left corner..